dns query get the ip of the target domain browser cache firefox(about:networking#dns) /etc/hosts os cache macos 查看 dns 请求日志 sudo log stream –predicate ‘process == “mDNSResponder”’ –info dns resolver /etc/resolv.conf arp -a 查看有没有 dns 服务器的 mac 地址 ARP request for the nameserver send dns query to get the ip of the domain arp 获取 gateway 的 mac